1. Field of the Invention
This invention relates generally to fluid dispensing valves, and more particularly to a dispensing closure having a fluid dispensing valve that functions to dispense fluid when a container bearing the dispensing closure is squeezed or when the dispensing closure is sucked upon and yet will not leak when the container is turned upside down or bumped.
2. Description of Related Art
Various automatic closing dispensing closures have been designed to fit on the container for dispensing beverages, liquids, soaps and other fluent materials that one might purchase at the supermarket. The closures may also be used on a baby drinking cup or cyclist water bottle whereupon the beverage would be dispensed by sucking on the closure or by squeezing the container.
Prior art closures primarily utilize a silicone dome dispensing system whereby the dome is penetrated by a pair of slits. The slits on the prior art domed surfaces open like petals when sufficient force is pushed upon it by the difference in the pressure in the container as compared to the pressure outside the container. Examples of these constructions are taught in Drobish et al., U.S. Pat. Nos. 4,728,006 and Rohr, 5,005,737 and 5,271,531.
There are several important disadvantages to the prior art construction. First, the slits used in the prior art are not effective in preventing accidental leakage if the container is bumped or dropped. Second, the slits must be added after the rubber dome is molded and therefore require a second operation, which adds to the cost of manufacturing the product.
Another prior art dispensing closure is shown in Imbery, Jr., U.S. Pat. No. 5,169,035. The Imbery, Jr. valve is excellent at venting air back into the container without allowing leakage through the venting flow path; however, the Imbery, Jr. closure does not teach a mechanism to control the outward flow of the fluid through the primary conduit.
In order to be effective, the fluid dispensing valve must meet three conditions. First, the valve should not dispense if the container is bumped or accidentally squeezed slightly. Second, the valve should vent and allow air to pass back through it into the container to make up the volume it has dispensed. Third, the valve must be inexpensive to manufacture.
The prior art teaches various valves used to regulate the flow of fluid into and out of a container. However, the prior art does not teach a valve that meets all three requirements of an effective fluid dispensing valve. The present invention fulfills these needs and provides further related advantages as described in the following summary.